Internal-combustion engine



Feb'. 1, 15927.

Filed Aug. 4. 1924 @mf/@r Y 3'. A. PARSONS ET AL 1 INTERNAL YCOMBUS'IIQN ENGINE s A n?. NA ES VE IN@ A STANu-:x S. Cea@ Fa. v1 1927.

C; A. PARSONS ET AL INTERNAL COMBUSTION ENGINE Filed Aug. 4, 1924 2 sheeis-snee't 2 f Dr 'R g 4: luuk-Nues.- CHAeLEs A. )Zqleswvs STA'vLsY S. C0014 Parenteel Feb. i,V i927.v

, CHARLES ALGERNON PARSONS, STANLEY SMITH COOK, AND HERBERT VGrllORiGrfEr KlVI- BER, OF NEWCASTLE-ON-TYNE, ENGLAND; SAID COOK AND SAID'KIMBER AS-V SIGNORS TO THE SAID PARSONS. Y Y

InTnnNAL-ooivriaiis'rioiv ENGINE.

Application ledvAugust 4, 1924, Serial No. 730,011, and iin `Great Britain August 8, 1923.

The present invention relates vto internal combustion engines and more particularly to devices suitable for starting oilengines in which the charge is ignited by the'lieat of the compression of the combustion air in the Working cylinder. Y

Large internal combustion engines are usually started by admitting compressed air into the Working cylinder until the engine has gained the necessary momentum to compress the air for combustion sufficiently to ensure the ignition of the charge.V

In the use of compressed air for starting purposes there is always a risk of premature explosion should the fuel be mixed With the air and the temperature be raised above the ignition pointl The object of the present invention is to obviate this danger and to use a gaseous medium under pressure which will not support combustion.

The inventionmore particularly consists in the improvements and arrangements hereinafter described and more particularly pointed out in the claims.

The invention will noW be described with reference to the accompanying drawings, i-n

which n Figure l is a section'on line 1 1 of Figure 4 and shows the starting device fitted to a cylinder' with means for regulating the compression pressure, Y

Figure 2 .hows a modification of' the means for regulating the compression pressure.

Figure 3 is a section onl the line 3-3 of Figure il, and

Figurev 4L is a plan of Figure l.

In carrying the invention into efect in one foi-in, as shown in Figures l, 3 and L,1:,and taking by Way of example its application to a heavy oil engine Working on the fourstroke cycle the head of the working cylinder is provided with an air admission valve, A an air duct, B, leading thereto and an exhaust valve, A, the valves, A. and A, being identical and operated by the rocking levers, C, C', actuated by cams mounted upon a cam shaft, l). In addition to this, a small steam valve, E, is provided in the cylinder head operated by one end of a rocking lever, F, mounted upon a rotatable eccentric, G, Which torms its fulcruin, ThlS rocking lever is provided at the other end fwith a roller, H,

which engages with a cam, I, mounted on the cam shaft, D. This eccentric may be partially rotated by means of a. control lever, l

K, which is adapted to be moved into the runningor into the starting position and is connected to the eccentric, G, by means of a lever arm, L, Aa link, M, and a lever arm, N, fixed to theveccentri'c. Tlierotation of the eccentric moves the roller, lil, of the rocking lever into or o-ut olvengageinent with the cam, the running7 position being'y that in Which the rocking lever is removed from engagement with the cam, as shown in dotted lines; A suitable fuel injection valve, E', is also provided in the cylinder'head and operated by the cam-shaft, D.

W'here the pressure of the available steam is less than the pressure to which air is normally compressed in the Working cylinder orcylinders, steam would only be admitted during that -portion of the stroke When the pressure in the cylinder had fallen below the pressure of the steam. In such cases, and in cases where the steam ,pressure is not sufficiently in excess of the pressure to which air is normally compressed in the .WorkingcyhV inder, means are provided for regulating the pressure in the cylinder immediately prior tothe admission of steam. This is effected by interconnecting the control lever, K, for operating the eccentric with a throttle valve, Q, situated inthe air duct, B, by means of a link, O, and lever arm, P. This throttle valve is so arranged that when the control lever is moved into the starting position the throttle valve is closed so as to restrict the passage of the air to the cylinder and the roller on the rocking leveris brought in contact with the cam. Since the air is rel stricted on the suction ystroke the compression is consequently reduced on thecoinpres-V sion stroke. rlhe starting7 position is shown in full lines in Figure 1.l ln this position of the control lever steam will be admitted to the cylinder by the operation of the cam While a very small quantity of air Will only be admitted to the cylinder, due to the restriction of the throttle valve.

When the engine has been running sufciently to ygain the required momentum the control lever is thrown over to the running position. This movement of the control one or more of the cylinders may be fittedr leverxopens vWide the throttle valve in the Y air duet and removes the rocking lever from Vcontact With the cam so that further steam is not admitted to the cylinder. The engine Will noW function in the ordinary Way.

In engines having more than one cylinder,

with the steam as desired. n Y Y YAccording to another form of the 1nvenvalve for starting `purposes tion, an example of which is illustrated in I' Figure 2, the compression pressuremay be .Y vtemporarily reduced by discharging all or part of the charge of air before the endofV the compression stroke. This is accomplished by mounting` the rocking lever, C, Which operates .the Vair valve, A, upon an eccentric, S, which can be rotated. This eccentric is connected byy an arm, T, iXed thereon and a rod, U, to the control lever, K, so as to be operated'at the same time as the rocking 'lever,JF, of the steam valve.

,centre beingshown by a chain dotted line.

\Vhen the control lever, K, is thrown over to the starting position the rocking lever, E, of the steam valve is brought into contact withrthe cam, I, so as to open the steam valve Vand at the same time the fulcrum of the rocking lever, C, vwhich operates the air valve -is brought nearer to .the cam shaft,

y Y as shown in full lines inrFigure 2. In this "positionthe roll-er, V, on the end of Ythe rocking .leverfollows closely the shape of the cam, which shape is suchv that the valve is held open, i. e. the closing ofthe air valve is delayed, until the endV or near the end of what is usually'the compression stroke. In this-manner the compression in the cylinder is regulated to the required amount.

Y Although the regulation of the 'pressure in the working cylinder' has been described above as beingcontrolled by the operation of thev air inlet valve, it is clearly to be understood that such regulation can also be effected by the operation of the exhaust valve, A', which is similar to the air valve,

A, in the same manner as the air valve, A,

'made according to the invention are that the air compressorcan be dispensed with, the cylinder can vbe maintained at a substantially higher temperature `throughout the stroke than Would be the case in starting Withcompressed air, the strains set up by variation of temperature are considerably reduced and the ignition of the irst charge is facilitated. y

We Wish it to be understood that the foregoing methods of carrying fthe linvention into eect are by Way of example only and that modifications thereof may vbe introduced Without departing from the'scope of the invention. y Y s Having now described our invention, what ive, claim as new and desire to secure by Letters Patent is'zl. A device for starting internal combustion engines yWorking on the vfour-stroke cycle, comprising in combination a steam valve situated in the cylinder head, means for actuating said'steam vvalve to admit steam on alternate,revolutions of the engine, an air valve admitting air to the cylinder, meansfor educting gases-from the cylinder, means for restricting the flow of air to said air valve during starting to reduce the compression on the compression stroke anda single instrumentality for bringing said steam valve and said restricting means into operation for starting, as set forth.

2.Y A device for starting internal combustion engines Working on the four-stroke cycle, comprising in combination a steam vvalve situated on the cylinder head, means for actuating said steam valve to admit steam on alternate revolutions of the engine, an air valve vadmitting air to the cylinder, a duct leadingl to saidv air valve, a throttle valve situated in saidduct, anvexhaust valve for educting gases from the cylinder and a single. instrumentality for closingsaid throt-V tle valve to reduce the compression on the compression stroke and for bringing said steam valve into operation, as set forth.

In testimony whereof We have signed our names to this specification. Y CHARLES ALGERNON PARSONS.

STANLEY SMITH COOK.

HERBERT GEORGE KIMBER,

lOl) 

